The Gates of Lodore confront us from the river like a misty portal in a Romantic ode. That must be why John Wesley Powell lifted the name from Robert Southey’s clunky poem, "The Cataract of Lodore." Jack Sumner, the most seasoned outdoorsman on the Colorado River Exploring Expedition of 1867, protested. He derided Southey’s poem as "musty trash." Sumner was right.

A radical turncoat, the David Horowitz of his time, Robert Southey is one of the more odious figures in the canon of English literature. As a young man, Southey dreamed of establishing a utopian community in the United States. His partner in this endeavor was Samuel Taylor Coleridge. They were going to call their commune of virtue on the banks of the Susquehanna: Pantisocracy. It never got beyond the lines on a map and an airy poem by Coleridge. Instead, unnerved by the French Revolution, Southey the utopian turned government snitch, informing to the British secret police on the subversive activities of a radical circle of English writers, including Hazlitt, Byron, Cobbett, Godwin and even his old friend Coleridge. Southey was rewarded for his treachery with the title of poet laureate.

There is the infamous Lake District incident, when a police snoop was dispatched to Wordsworth’s cottage at Grasmere, perhaps on information passed along from Southey. As the officer crouched beneath an open window, he eavesdropped on a raging debate between Wordsworth and Coleridge over the merits of Spinoza’s thoughts on government. The officer wrote excitedly back to the Home Office with the news that sedition was indeed afoot in the English countryside and that the poets were in covert contact with an agent of the French menace known as "the Spy Nozi."

Yes, we live in a new age of government paranoia, of snitches, spies and informants. But must we commemorate them in our national parks?

In any event, even the best English Romantic poetry (Keats’ "Ode to Autumn", say, or Coleridge’s "Frost at Midnight") doesn’t hint at the mysteries to be found in the canyons of the Green River, which over the eons have been the haunts of some of the strangest creatures on the planet: the Allosaurus, the sabre-toothed herbivore (Why the long teeth? Think rough sex), the ringtail cat and the Bureau of Reclamation engineer.

Lodore is a deep and narrow fissure in the High Uintas, that odd east/west range that strides across northern Utah. It is a canyon of echoes and shadows. Cool and dark. Spooky. Here the rocks show their age.

And old they are. Very old. The red quartzite of the Lodore Formation dates back nearly a billion years to the Cambrian period. Back to a time-an unimaginably extended epoch of time-when the future direction that life on Earth would take was being decided, a drama which the great evolutionary biologist Stephen Jay Gould eloquently narrates in his fascinating and controversial book Wonderful Life: the Burgess Shale and the Nature of History. Would the chordata prevail over the spineless soft-tissued oddities, setting the stage for the rise of the vertebrates? For Democrats (and some environmentalists), it remains an open question.

In addition to the Gould and my river maps, I’ve brought along three other volumes, which, for handy access, I’ve wedged under a strap in the bow of Weisheit’s raft: David Allen Sibley’s Field Guide to the Birds of Western North America, John Wesley Powell’s The Exploration of the Colorado River and Its Canyons and G.E. Untermann’s Guide to the Geology of Dinosaur National Monument. Putting the books in the bow of the raft will prove to be a fatal mistake-fatal for the books, anyway. (And, perhaps, for me too, given that I cohabit with a librarian who puts the rough treatment of texts on the same unpardonable level of moral degeneracy as the abuse of animals.)

The Untermann volume is an heretical choice, which Weisheit immediately notices and passes condemnatory judgment upon. Let this be known: the Riverkeeper doesn’t forget and he doesn’t forgive.

Like many progressives of his time, Untermann was a cheerleader for the Echo Park Dam back in the 1950s, even though the concrete monstrosity would have flooded most of the geological, archaeological and paleontological sites that the geologist writes about with such zest and awe in his little monograph.

There was a time when the American left, of which Untermann was a member, viewed hydro-power as the democratizing salvation for the industrial economy, promising a future of cheap power, high-paying jobs and freedom from the shackles of big oil. (Go read John Gunther’s Inside U.S.A. for a taste of just how deeply these hydro-delusions were cherished by liberals and leftists of mid-century America.) Inexplicably, many progressives, including some self-advertised environmentalists, persist in promoting these long discredited myths in the name of saving the planet from global warming.

Consider the case of liberal icon Woody Guthrie, the Okie troubadour. In the 1940s, Guthrie prostituted himself for the Department of the Interior, which paid him to write propaganda songs to promote the big salmon-killing dams on the Columbia River. While penning "Roll On Columbia" and similar doggerel, the folksinger watched silently from his rented house in Portland as the river tribes were forcibly evicted from their villages and salmon fishing sites to make way for the dams. The Red Okie remained mute in the face of cultural genocide. As for the electrical power, it sure wasn’t disseminated to Guthrie’s rural poor, never mind the dispossessed tribes of Celilo and Wishram. Most of it crackled down giant powerlines to the H-bomb making factories at the Hanford Nuclear Reservation. Guthrie never apologized for being the Leni Riefenstahl of the Columbia and Untermann, as far as I can tell, never retracted his support for the proposed dams that would have turned Dinosaur National Monument into a holding tank for dead water and toxic silt.

Still I admire the way the man writes. The prose in most geology books is as arid as the floor of Death Valley. But Untermann writes about fractures and faults, upthrusts and grabens, as if telling the story of a mighty battle, a thrilling dialectical struggle between the competing forces on the crust of the Earth.

Untermann knew a little about dialectics. As I waited to rendezvous with Craig and Chris in Vernal, I took a stroll through the town’s top attraction: the Utah Field House Museum of Natural History. I’ve toured many natural history museums, from New York to Paris. The sprawling Field Museum in Chicago is my favorite haunt, but Vernal’s more compact and concentrated offering is a close second. The building unfolds like a strand of DNA, spiraling up through the ages of the earth, from trilobite fossils of the pre-Cambrian to a stunning mural of petrified maple leaves and fossilized bird feathers from the Green River shales of the Eocene, which are currently being cannibalized in the Bush oil rush.

Thanks to the rich trove of fossil-bearing loads from the Morrison Formation in Dinosaur National Monument, the little museum in Vernal offers some of the most complete dinosaur skeletons in the world, including a stegosaurus, a rare Haplocanthosaurus and one of the most ferocious predators of the Jurassic Period, the allosaurus, a sleeker, faster and more colorful version of T-Rex. T-Rex with feathers.

The tour concludes in a room of vibrantly colored oil paintings featuring fearsome battles between dinosaurs. I am a sucker for dioramas and these scenes of terror and tragedy in the Triassic age are incredibly exciting. They were all painted by Untermann’s father, Ernest.

Untermann, Sr. was one of the founders of the Field House Museum. He was also one of the founders of the American Socialist Party and an early translator of the works of Karl Marx into English. Apparently a committed Trotskyist, in 1935 Ernest wrote a book-length attack on the Stalin titled Lenin’s Maggot. Born in Brandenberg, Germany in 1864, Untermann came to Vernal, Utah in 1919 looking to strike it rich in the gold fields. But the gold rush was long over and Untermann was soon distracted though by excavations of fossils in Dinosaur National Monument by paleontologist Earl Douglass, who had been hired by Andrew Carnegie to bring back to Philadelphia a dinosaur "as big as a barn."

After a few years, Untermann left Utah for Milwaukee, where he ran the city zoo, and Chicago, where he studied painting at the Art Institute. By 1940, Ernest was back in Vernal, where over the next 15 years, he executed more than 100 paintings of life in the Uinta region during the thrilling Mesozoic period. Like many socialists of his era, he lived a long and adventuresome life, dying in 1956 at the age of 92.

Busloads of Utah school children are shipped off to Vernal every year for an obligatory visit to the museum. It must be a mind-blowing experience for them. Although Mormon doctrine embraces the existence of dinosaurs (the Terrible Lizards are good for the economy and, given the heavy tithing obligations imposed on the Saints, for church coffers as well), it also teaches that the Earth is only 7,000 years old-a chronology that the museum exhibits dispute with what Gould called "geology’s most frightening facts." But complex geological timelines depicting the fossil record are easily forgotten by the minds of young Mormons (or adult Gentiles, for that matter). Less so are the subversive messages encoded in the dinosaur dialectics painted by the Marxist of the Uintas.

As I scan the maroon cliffs of Lodore, trying to make sense of the geological processes Untermann describes, I am distracted by a growling sound emerging from the river itself. We round a sharp bend in the canyon and are rudely jerked into our first rapids: a short, violent run of water. The tumult is over almost before it began. A case of premature excitation. Not to worry. There are thirty more where that one came from. Bigger, wetter, nastier.

* * *

We break for lunch at a place called Winnie’s Grotto, a dark slot canyon draped with maidenhair ferns and fuzzy mosses–a moist exemplar of the marvels microclimate. A pair of ravens scrutinize our meal, but noisily dismiss the fare of smoked oysters with Pringles chips and wheel off in search of more robust offerings.

Chris hands me a frosty Tecate. I remove my jacket and recline on a warm slab of stone that only months ago was submerged under four-feet of calamitous water.

"Pssst."

It’s Judy again. This time she seems to have sprung from behind a stand of rippling willow trees-one of the few such groves left in the canyon thanks to the dam, the dropping water table, the invasion of the tamarisks. These stage actresses sure know how to maximize the effect of their entrances.

"Can I ask you a favor?"

"Sure." Thinking she needs me to perform a manly task, like setting up the shitter or standing between her and a marauding tarantula. In post-feminist America, it feels good to finally be needed.

"Can you take your shirt off?"

This is one request I wasn’t expecting. But …

"Or at least turn it inside out. It’s disturbing me."

I look down at one of my favorite shirts. I’ve worn it once a week for six years. The cotton is pliant and soft, pleasantly frayed, familiarly stained. Nearing perfection. The offensive image on the front was designed by my pal Steve Kelly, the environmentalist and artist in Bozeman, Montana. It reproduces one of Kelly’s best paintings, a field of slain bison, their blood staining the snowy plains. The caption above the startling image reads: "Grown in Yellowstone, Slaughtered in Montana."

The painting, which Kelly placed on billboards along I-90, protests the ongoing killing of Yellowstone’s wild bison on the bogus pretext of protecting cattle from being infected with brucellosis. I’ve nearly come to blows over this shirt before: in a bar in Salmon, Idaho (one of America’s meanest towns) and at a rusty diner in the cattleburg of Burns, Oregon.

But here in the depths of Lodore, in the blood red basement of the Uintas? This is the last place in the world I’d expect to be censored. But Judy is an animal lover. She works closely with the Humane Society in Moab. The shirt clearly upsets her. Still I’m usually a cantankerous asshole at precisely these critical moments and I surprise myself by relenting without even a nasty quip. Kelly’s painting has done its work. I reverse the shirt, but secretly vow to flash its brutal truth if we ever encounter one of them damn park rangers.

Jennifer snaps the tension by popping another Tecate and retelling a joke that the Riverkeeper still doesn’t get: "A termite walks into a saloon and asks: Is the bartender here?"